Added metadata, moved partials into main text body.
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Peter Boy
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= How to debug printing issues
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= CUPS – How to Debug Printing Issues
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Brandon Nielsen ; Zdenek Dohnal
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:revnumber: F35 onwards
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:revdate: 2022-02-10
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:category: Troubleshooting
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:tags: How-to printer
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:category: Printing
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:tags: How-to, Printer, Troubleshooting
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:page-aliases: how-to-debug-printing-problems.adoc
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If you are experiencing a problem with printing, please take a look at the https://fedoraproject.org/wiki/Bugs/Common[common bugs] page before filing a bug. If the problem you are seeing is not listed there or none of the workarounds seem to help, please consider xref:cups-filing-a-bug-report.adoc#_filing_a_bug_report[filing a bug report] to help us make Fedora run better on your hardware.
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= How to debug scanning issues
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= CUPS – How to Debug Scanning Issues
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Brandon Nielsen ;
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:revnumber: unspecified
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:revdate: 2021-06-16
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:category: Troubleshooting
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:tags: How-to scanners
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:category: Scanner
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:tags: How-to, Scanner, Cups, Troubleshooting
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:page-aliases: how-to-debug-scanning-problems.adoc
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= Filing a CUPS Bug Report
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= CUPS – Filing a Bug Report
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Brandon Nielsen
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:revnumber: all
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:revdate: 2022-05-15
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:category: Bugs
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:tags: How-to Bug-Report cups
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//:imagesdir: ./images
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:category: Printing
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:tags: How-to Bug-Report Cups
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// include::partial$attributes.adoc[]
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ifdef::context[:parent-context: {context}]
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:context: cups-known-issues
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[id='cups-known-issues']
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= Known issues
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:toc:
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= CUPS – Known Issues
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Brandon Nielsen
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:revnumber: F31 onwards
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:revdate: 2021-06-16
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:category: Printing
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:tags: How-to, Cups, Workstation, Gnome
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include::{partialsdir}/con_cups-known-issues.adoc[leveloffset=+1]
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ifdef::parent-context[:context: {parent-context}]
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ifndef::parent-context[:!context:]
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Here are several known issues, which arise with certain circumstances, and there isn't general solution or upstream didn't want to add the solution to its project:
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== cups-browsed
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=== Cannot print due 'No destination hostname provided by cups-browsed, is it running?'
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cups-browsed sometimes loses connection to print server (usually with old ones, like cups-1.4.2) when laptop changes network connection (change of WiFi network or after hibernate/suspend). You can make printing working again with cancelling your jobs and restarting cups-browsed by
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----
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$ cancel -a
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$ sudo systemctl restart cups-browsed
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----
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=== cups-browsed consumes large amount of CPU
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Creating local printer queues takes long time for some printers with larger PPD file, so timeout of http connection will time out and it creates infinite loop of creating local printer queues. To solve this issue, please add
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----
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HttpLocalTimeout N
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HttpRemoteTimeout N
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----
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into [filename]`/etc/cups/cups-browsed.conf`, where `N` is number of seconds after which connection is timed out. Then restart cups-browsed service. This option is currently in Fedora 27 and above.
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=== [SINCE FEDORA 27] cups-browsed creates different printer queue names than before
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This issue is connected to remote cups queues, which are advertised by older CUPS version (usually below cups-1.5, e.g. RHEL 6). Cups-browsed creates local print queues named by printer's DNS-SD ID by default and naming by remote cups queue is enabled again by adding:
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----
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LocalQueueNamingRemoteCUPS RemoteName
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----
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into [filename]`/etc/cups/cups-browsed.conf` and restart cups-browsed service.
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== cups-filters
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=== Printing takes a long time or doesn't print at all
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When your printer needs a lot of time to do printing (from your POV) or doesn't print at all (some Xerox printers have such problems with gs renderer, so they are working again only with pdftops renderer), you can try to change the default postscript renderer. The default renderer in Fedora for most printers is gs filter from Ghostscript, but we have pdftops filter from Poppler for Brother, Minolta and Konica Minolta printers - this setup is called hybrid.
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Other available renderer setups are gs (from Ghostscript), pdftops and pdftocairo (from Poppler), mupdf (from mupdf) and acroread (from adobe reader, not in Fedora official repositories), then you can set different default renderer for your print queue like this:
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----
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# lpadmin -p <printer-name> -o pdftops-renderer-default=gs/pdftops/pdftocairo/mudpf/acroread/hybrid
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----
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*BEWARE:* Most 'slow' printing issues are caused by PDF creating applications, which generates bad PDF file - and that bad generated PDF file is mostly the core of problem. To sum it up, slow printing issue can rise again with different PDF file, then it is on user's decision: if he wants to print fast and probably sometimes change the default renderer, or slow printing is not such critical issue.
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== CUPS
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=== [Fixed in F33 and later] Firefox, Evince (PDF viewer), GVim, Gedit, Gnome Control Center show a 'dummy'/duplicate print queue, which doesn't work
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This bug is connected to every application which uses GTK print dialog. GTK dialog decided to take information about available from two sources - mDNS messages from Avahi and CUPS - this dummy/duplicate print queue is a print queue GTK created in its dialog based on Avahi messages, but it doesn't exist in CUPS, because no one created it, and later GTK behaves like it exists in CUPS. So every time an user wants to print, GTK sends a request to CUPS for this queue, but it gets dropped by CUPS because the queue doesn't exist.
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The feature which GTK is trying to do here is called CUPS temporary queues - GTK developers is currently working on a immediate fix in this https://bugzilla.redhat.com/show_bug.cgi?id=1784449[bugzilla]. The future plan is to use https://github.com/OpenPrinting/cpdb-backend-cups[cpdb-backend-cups] backend in GTK, but right now we are focusing on the intermediate fix.
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=== CUPS doesn't take nicely some kinds of FQDN
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CUPS sometimes has problems with some kinds of FQDN - that means when you use FQDN in [option]`BrowsePoll` directive in [filename]`/etc/cups/cups-browsed.conf`, CUPS doesn't recognize it as valid hostname - it is solved by adding:
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----
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ServerAlias your.own.fully.qualified.hostname.com
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----
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into [filename]`/etc/cups/client.conf` and restarting cups service.
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=== There are less options available if the device is used as driverless than with a classic driver
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The similar situation can happen with *sane-airscan* supported scanners. Some devices declare less options via protocols - f.e. IPP 2.0+, WSD, eSCL - which support driverless solutions than via classic drivers. Usually it is an issue with device's firmware, which can be verify by checking the output of the following command:
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----
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$ ipptool -tv <ipp_device_uri> get-printer-attributes.test
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----
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The commands does the same IPP request which is done when a temporary queue appears in the print dialog or when you install the queue permanently. The printer options are set from the IPP response for this request, so if the option is missing in the response, CUPS cannot generate such a printer option. The solution is to try to update the device firmware, report the issue to the device manufacturer and at https://bugzilla.redhat.com[bugzilla] with logs.
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=== [F33+] Printing via IPPS doesn't work
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Fedora 33 came up with a raised bar regarding crypto-policies, so SSL and older TLS protocols are disabled on system level. The change breaks printing via IPPS to devices which don't support newer protocols. You can set back legacy crypto support in crypto-policies via:
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----
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$ sudo update-crypto-policies --set DEFAULT:FEDORA32
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----
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The policy change transitionally has an impact on devices found by cups-browsed, because the daemon prefers IPPS uris if they are reported as available by printer/server.
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== HPLIP
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First I would like to mention that we are not responsible for support HPLIP, which is downloaded and installed from HP website. Please install hplip rpms from official Fedora repositories at most cases.
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=== Hp-plugin: file does not match its checksum. File may have been corrupted or altered
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This common error is mostly caused by external causes (server outage, network outage), when wget tries to download plugin, but it returns only error message. It is connected with message:
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----
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Plugin download failed with error code = N
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----
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where `N` is return value of [command]`wget` ([command]`man wget`), which is used for downloading proprietary plugin. Solutions for this issue may vary - you can wait until servers go up again or try to install plugin, which you download manually from http://www.openprinting.org/download/printdriver/auxfiles/HP/plugins/ (select "Select and install an existing local copy of the plug-in file" during [command]`hp-setup` or [command]`hp-plugin`).
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=== Unable to load cupsext
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This error can occur when hplip is installed from HP website, or its dependencies are mixed python2 and python3 packages or installed by pip. This is solved by removing all hplip packages (hplip, hplip-gui, hplip-libs, hplip-common, libsane-hpiao) and installing them again all from repositories.
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=== Missing hplip-gui
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GUI tools and GUI parts of HP commands are moved to hplip-gui subpackage, because the main package can work without GUI, so the main package is smaller. The outcome of this decision is HP commands need to be run with `-i` option for interactive mode, or hplip-gui subpackage needs to be installed.
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Tools, which need to be run with `-i` option for CLI or need to have hplip-gui installed for GUI:
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----
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hp-align
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hp-clean
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hp-colorcal
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hp-diagnose_queues
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hp-fab
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hp-firmware
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hp-info
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hp-plugin
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hp-sendfax
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hp-setup
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hp-testpage
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hp-unload
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----
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Tools, which are in hplip-gui:
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----
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hp-check
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hp-print
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hp-systray
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hp-toolbox
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hp-devicesettings
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hp-faxsetup
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hp-linefeedcal
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hp-makecopies
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hp-printsettings
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hp-wificonfig
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----
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=== HP printer isn't discovered, doesn't print or doesn't print well
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Some HP printers don't work well with URIs provided by CUPS (dnssd, usb, ipp) or they need proprietary plugin from HP, which cannot be in Fedora because of licensing issues. For such printers please try to run:
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----
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hp-setup -i -g
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----
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for interactive mode, or:
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----
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hp-setup -g
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----
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for graphic mode. This command installs HP printers and HP scanners. If you have issue about HP printer/HP scanner, which isn't discovered, doesn't print or doesn't print well, please try to install it by [command]`hp-setup`, if it helps. If it doesn't help, please file a bugzilla, attach output of hp-setup and mention that you tried [command]`hp-setup`.
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=== Device which needs plugin does not work after HPLIP update
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Devices which need plugin can stop to work after update to newer HPLIP version - it is due the check for plugin version in the code. The check is necessary to prevent inconsitencies when new features in open sourced HPLIP need new proprietary libraries from plugin. To make your printer work again, just download and install plugin again with:
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----
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$ hp-plugin -i
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----
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=== Devices which require a binary plugin stopped to work on Fedora Silverblue/CoreOS
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Devices which require a HP close source binary plugin need to have plugin installed every time you start/restart your PC by default. HP closed source script installs the plugins into a readonly directories, so the plugins are removed once you start/restart Fedora. The workaround is to try if your device supports driverless printing and scanning, try hplip-plugin package from RPMFusion or keep installing the plugin everytime you want to print.
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== golang-github-openprinting-ipp-usb
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=== USB printer/scanner doesn't work due a conflict on USB port
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*ipp-usb* daemon keeps the USB port of IPP-over-USB device opened for any possible IPP communication in the future, which blocks the port for other drivers (f.e. HPLIP, gutenprint, sane-backends...).
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For printers the solution is to _uninstall the queue with the driver_ by:
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----
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$ lpadmin -x <queue_name>
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----
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and start using the one from *ipp-usb* (as a xref:cups-terminology.adoc#_temporary_print_queues[CUPS temporary queue] or install a permanent one - the default device uri is `ipp://localhost:60000/ipp/print`).
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In case of scanners *sane-airscan* automatically picks up the virtual device from *ipp-usb* if the device is capable of using WSD or eSCL protocols. However, if the scanner had been supported by classic scanner driver such as hplip or sane-backends and is now claimed by *ipp-usb* because it supports *IPP-over-USB* driverless standard, the old scanner is still shown, but it won't work for scanning due USB conflict. It happens because classic backends just list any device which they can find on USB interfaces and matches the description the backend supports, but backends don't check whether they actually can communicate with the device until they try to open the USB port for scanning process itself. This becomes a problem for scanning applications, which automatically choose the previous scanner as a default choice for scanning (such as _Simple Scan_) - users have to pick a driverless scanner from the list of available scanners before they scan.
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The scanner device discovered by classic SANE backends can be disabled from showing it among available scanners by commenting out its entry in backend's configuration file located in [filename]`/etc/sane.d` or the whole backend name in [filename]`/etc/sane.d/dll.conf`/[filename]`/etc/sane.d/dll.d`, f.e. Canon MF440 Series is reported by `pixma` and `airscan` backends, but only `airscan` works because it is a backend based on network protocol and USB interface is claimed by `ipp-usb`, so we will disable the `pixma` backend by commenting its line in [filename]`/etc/sane.d/dll.conf`:
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----
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$ cat /etc/sane.d/dll.conf
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...
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pint
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#pixma
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plustek
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...
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----
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If *ipp-usb* created device doesn't match your use case (the options you use are missing, the device doesn't work even if it is IPP-over-USB supported), please report the issue together with logs from [filename]`/var/log/ipp-usb/` directory at https://bugzilla.redhat.com[bugzilla]. *ipp-usb* itself supports quirks, which allows you to set the daemon to ignore your device and you can switch back to a classic driver. The steps are following:
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- get the device model name f.e. Canon MF440 Series:
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----
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$ sudo ipp-usb check
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Configuration files: OK
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IPP over USB devices:
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Num Device Vndr:Prod Model
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1. Bus 001 Device 005 04a9:2823 "Canon MF440 Series"
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----
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- create a quirk file in [filename]`/etc/ipp-usb/quirks` directory in the format below:
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----
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$ cat /etc/ipp-usb/quirks/canon.conf
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[Canon MF440 Series]
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blacklist = true
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----
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- restart the `ipp-usb` service:
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----
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$ sudo systemctl restart ipp-usb
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----
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== sane-airscan
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=== There are less options available if the device is discovered by sane-airscan than with a classic driver
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The similar situation can happen with `everywhere` or `driverless` printer models. Some devices declare less options via protocols - f.e. IPP 2.0+, WSD, eSCL - which support driverless solutions than via classic drivers. Usually it is an issue with device's firmware, which can be verify in sane-airscan debug logs and network traffic. The solution is to try to update the device firmware, report the issue to the device manufacturer and at https://bugzilla.redhat.com[bugzilla] with logs.
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@ -1,10 +1,99 @@
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ifdef::context[:parent-context: {context}]
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:context: cups-terminology
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[id='cups-terminology']
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= Printing and scanning terminology
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:toc:
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= CUPS – Printing and Scanning Terminology
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Brandon Nielsen
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:revnumber: F31 onwards
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:revdate: 2021-06-16
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:category: Printing
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:tags: How-to, Cups, Workstation, Gnome
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== Printing
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=== Print queue
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Abstraction unit in CUPS for a printer - it has a device uri, which represents connection to the device, and can exist with classic driver (PPD file from different package) or without (driverless printing). The entries you see in print dialogs and settings are those _print queues_. They can be _permanent or temporary_.
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=== Permanent print queues
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The queues with classic driver or driverless print queue which need to be shared further down the network.
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=== Temporary print queues
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The queue which don't need to be installed at all - they show up during print dialog and they disappear once the printing is done successfully. They rely on _driverless printing_.
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=== Remote CUPS queue
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The queue on the different machine, where other cupsd process is running, than on the local machine. They are usually found in enterprise solutions, where printers aren't in the same network as users or if admin wants a centralized monitoring above all printers. In such solutions, users set up _cups-browsed_ to install remote CUPS queue as local queues via _BrowsePoll_ directive, or install a specific queue via GNOME. There can be a solution how to redirect mDNS messages which CUPS server advertises to the networks with users, but I haven't been to setup this correctly yet.
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=== Classic drivers
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Those are the binaries and PPD files, which need to be installed for the device to work. This is older way of supporting devices, which will go away in the future.
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=== Driverless printing (wireless/ethernet)
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Most of modern devices (2010+) complies to AirPrint, Mopria or IPP Everywhere standard, which means they don't need a classic driver for being able to print. Those devices have IPP (Internet Printing Protocol) 2.0+ implemented within, are capable to 'advertise' themselves via mDNS and they support document formats like PDF, PCLm, JPEG, Apple Raster or PWG Raster.
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There are several prerequitises which need to fulfill in OS to have an access to the driverless feature:
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* avahi-daemon must run
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* there needs to be a '.local' address resolver active - systemd-resolved or nss-mdns
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* the device itself must have IPP port (631) and Bonjour/MDNS enabled
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* IPP and MDNS need to be enabled in firewall
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How does the driverless printing work under the roof (put it simply):
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* CUPS sees the printer in mDNS messages via Avahi
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* CUPS will find out the printer capabilities via IPP
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* if there is a print job, CUPS will set up the filter chain to convert the incoming file into document format which printer understands (Apple Raster, PDF, PWG Raster, PCLm, JPEG)
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In case it is needed, PPD file is generated by PPD generator in CUPS or by _driverless_ binary.
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One of the features which use driverless printing is _CUPS temporary queues_.
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See xref:cups-useful-tricks.adoc#_how_to_find_out_whether_my_printer_is_capable_of_driverless_printing[manual] how to check if your printer is capable of driverless printing.
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=== Printing using a driver
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This printing is similar to driverless printing in matter of setting up a filter chain, but:
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* it can use limited mDNS and IPP functionality or it doesn't use them at all
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* all information about device capabilities is taken from PPD (Postscript Printer Description) file
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* can use a specialized filters and specialized communication with the device (depends on driver)
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The downsides of this approach is to rely on 3rd party drivers, you need to always install a permanent queue for it and it will go away in the future.
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=== Raw queue
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No filters are started by CUPS if you print to such a queue, the data are sent as they are to the target, no options are applied by CUPS - all regardless of incoming document format. It is required the application you use for printing sends a printer-ready data (in the correct format, with all chosen options applied) or the destination is set to the desired settings (f.e. printer/print server is set to do two-sided-long-edge duplex with grayscale settings, so every document printed will have this settings and user won't be able to change it in an application).
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This approach is usually set for printing to older label printers via a specific application, or, in the past, for printing to remote CUPS queue. Because CUPS has no way how to provide common user experience (finding out printer properties, converting various document formats into a document format the printer accepts, setting printing options) for such queues, their usage is deprecated and it will be removed in the future (in CUPS 3.X).
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=== Raw printing
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|
||||
Raw printing happens if CUPS receives a file in document format which printer accepts directly and CUPS recognizes the format based on rules from its MIME database. CUPS daemon doesn't start any filters for such a job (it might encapsulate options into IPP packet, if the connection with the printer is over IPP) with exception for PDFs, where the _pdftopdf_ filter is started to apply generic settings like scaling, rotation etc. Raw printing itself happens on print queues with classic driver and driverless print queues. This functionality stays with CUPS 3.X.
|
||||
|
||||
The difference between raw printing and raw queue is the raw printing is a situation which happens if CUPS daemon gets a file in format which printer accepts, so the daemon does not spawn additional filters for such job (with PDF being an exception), and spawns filters for document formats, which are not acceptable by the printer directly, whereas the raw queue is a queue, which CUPS daemon does not spawn any filters in any circumstances, and behaves like a Unix pipeline.
|
||||
|
||||
=== Printer applications
|
||||
|
||||
The binaries which provide support for older devices which aren't capable of complying to driverless standards. The core idea is they will be capable of accepting the old driver and then advertise itself as a device capable of driverless printing. Then the new CUPS will be able to see them and user will be able to print via them as if they were temporary queues. The currently available printer applications in Fedora are _ippeveprinter_ (a part of CUPS - see cups-printerapp package) and _lprint_ (provides support for devices which requires raw printing - mostly label printers). Other printer applications like https://github.com/OpenPrinting/ps-printer-app[ps-printer-app], https://github.com/OpenPrinting/ghostscript-printer-app[ghostscript-printer-app], https://github.com/OpenPrinting/hplip-printer-app[hplip-printer-app] and https://github.com/OpenPrinting/gutenprint-printer-app[gutenprint-printer-app] are currently available as SNAPs until cups-filters 2.0 is released and packaged. Printer applications are, except for _ippeveprinter_, written using _PAPPL_ library, so such printer application provides CLI interface and Web Interface for users to interact with.
|
||||
|
||||
=== Driverless printing (USB)
|
||||
|
||||
Driverless printing has its variant for devices which are connected via USB - it is covered by 'IPP over USB' standard. For make it work, you need 'ipp-usb' package, which will register the device with Avahi on localhost - then USB device will look as a wireless/ethernet device. The discovery/printing looks the same as with a wireless/ethernet device with driverless support.
|
||||
|
||||
See xref:cups-useful-tricks.adoc#_how_to_find_out_whether_my_printer_is_capable_of_driverless_printing[manual] how to check for IPP-over-USB.
|
||||
|
||||
== Scanning
|
||||
|
||||
=== Classic scanning (via hplip and sane-backends)
|
||||
|
||||
The classic scanning works via backends, which are binaries for communication with device. There are several backends, usually created by reverse engineering communication between scanner and MS Windows driver. None of classic backends implements a protocol, which is compatible with most devices available.
|
||||
|
||||
=== Driverless scanning
|
||||
|
||||
The driverless scanning uses sane-escl (not built in Fedora) and sane-airscan backends for communicating with newer devices. Those newer devices usually support eSCL (based on AirScan protocol by Apple) or WSD (Web Services for Devices by Microsoft), which _sane-airscan_ is able to use.
|
||||
|
||||
Regarding USB scanning, it has the same requirement as printing. The device must support IPP over USB driverless standard and _ipp-usb_ package must be installed to get driverless scanning via USB - the package is required because it creates a driverless interface over USB interface which _sane-airscan_ uses for driverless communication with device.
|
||||
|
||||
|
||||
include::{partialsdir}/con_cups-terminology-for-printing-and-scanning.adoc[leveloffset=+1]
|
||||
|
||||
ifdef::parent-context[:context: {parent-context}]
|
||||
ifndef::parent-context[:!context:]
|
||||
|
|
|
|||
|
|
@ -1,10 +1,405 @@
|
|||
ifdef::context[:parent-context: {context}]
|
||||
:context: cups-useful-tricks
|
||||
[id='cups-useful-tricks']
|
||||
= Useful tricks
|
||||
:toc:
|
||||
= CUPS – Useful Tricks
|
||||
Brandon Nielsen
|
||||
:revnumber: F31 onwards
|
||||
:revdate: 2021-06-16
|
||||
:category: Printing
|
||||
:tags: How-to, Cups, Workstation, Gnome
|
||||
|
||||
include::{partialsdir}/con_cups-useful-tricks.adoc[leveloffset=+1]
|
||||
|
||||
ifdef::parent-context[:context: {parent-context}]
|
||||
ifndef::parent-context[:!context:]
|
||||
== How to install a print queue
|
||||
|
||||
The fact whether you have to install a printer or not depends on several things:
|
||||
|
||||
* what is the device you want to install - a printer from remote CUPS server (called remote print queue) or a printer,
|
||||
* where is the device you want to install - connected by USB to your PC, in your local network, in a different network or installed on a remote server,
|
||||
* how old is the device you want to install:
|
||||
** standalone printers - most SOHO (Small Office, Home Office) and office printers made after 2010 have at least one way of supporting driverless printing, older devices depend on drivers - classic or printer applications,
|
||||
** remote print queues on a server - any OS with CUPS 2.2.8 and newer or OS where IPP Everywhere support was backported (f.e. RHEL 8) are capable of supporting IPP Everywhere, otherwise a combination of driver and raw queue is needed in client-server communication,
|
||||
* what is the purpose of the device where you install the printer - endpoint device, which is used by user as a desktop, or a server, which shares the installed printers further,
|
||||
* what are your personal preferences - using or not using IPP protocol, using or not using mDNS for autoinstallation if possible from network layout.
|
||||
|
||||
So there are several user stories based on those dependencies, which are described further down.
|
||||
|
||||
=== Common user stories
|
||||
|
||||
==== I have a printer made after 2015, I'm at home and want to print from my PC
|
||||
|
||||
* the most common setup on desktop
|
||||
* the printer is new enough to support driverless standards via USB and network, so driverless support doesn't depend on your connection
|
||||
* the PC is an endpoint device, I don't want to share the printer
|
||||
* I don't mind using mDNS and IPP, mDNS is enabled in my firewall, IPP and mDNS (or similar settings) are enabled on the printer, and mDNS resolution works (checked by pinging .local hostname)
|
||||
|
||||
CUPS temporary queues for xref:_how_to_setup_cups_temporary_queues_with_usb_printer[USB] or xref:_how_to_setup_cups_temporary_queues_with_network_printer[network] are ideal for this use case.
|
||||
|
||||
==== I have an older printer, I'm at home and want to print from my PC
|
||||
|
||||
* the printer doesn't have a driverless support - check via xref:_how_to_find_out_whether_my_printer_is_capable_of_driverless_printing?[ipptool] for network printers (if the printer has IPP support and you enable the port) and via xref:_how_to_find_out_if_my_usb_device_supports_ipp_over_usb[lsusb] for USB printers,
|
||||
* my PC is an endpoint device
|
||||
|
||||
Currently there are two options - install the printer in xref:_how_to_install_a_printer_via_printer_application_in_snap_and_making_it_available_for_cups[printer application] and CUPS will automatically see it, or install it with classic driver xref:_how_to_install_a_permanent_print_queue[permanently]. Installation with classic driver is deprecated and will be removed in CUPS 3.0.
|
||||
|
||||
==== I'm in a company which has a print server where office printers are installed, I want to print to the print server - no mDNS, but with driverless
|
||||
|
||||
* the print server supports IPP Everywhere and is in a different network or doesn't register on mDNS, or I don't want to use mDNS
|
||||
* remote print queue has the URI ipp://<server_hostname>:631/printers/<queue_name>, where <server_hostname> is the hostname of print server and <queue_name> is a name of a print queue I want to connect to
|
||||
* xref:_how_to_find_out_whether_my_printer_is_capable_of_driverless_printing?[ipptool] command passes if the URI is used
|
||||
|
||||
Such printers has to be installed xref:_how_to_install_a_permanent_print_queue[permanently] with IPP Everywhere driver.
|
||||
|
||||
==== I'm in a company which has a printer server where office printers are installed, I want to print to the print server - with working mDNS in local network
|
||||
|
||||
Such remote printers are discovered automatically via mDNS and used as xref:_how_to_setup_cups_temporary_queues_with_network_printer[CUPS temporary queues] on network - they are seen on mDNS and automatically picked up by dialogs.
|
||||
|
||||
==== I want to print, but I don't want to or can't use mDNS, regardless whether my printer supports driverless printing
|
||||
|
||||
Every printer which can't be discovered by mDNS has to be installed xref:_how_to_install_a_permanent_print_queue[permanently] in CUPS or, in CUPS 3.0, by printer profile.
|
||||
|
||||
. Driverless printers:
|
||||
* all of them supported by *IPP Everywhere* model under Manufacturer entry in CUPS Web UI and as *everywhere* in CLI
|
||||
* types based on origin:
|
||||
** Network:
|
||||
*** URI: ipp://<hostname_or_ip>:631/ipp/print , where <hostname_or_ip> is hostname or IP address of the printer
|
||||
** IPP-over-USB printers via ipp-usb:
|
||||
*** URI: ipp://localhost:60000/ipp/print
|
||||
** Printers installed via printer application:
|
||||
*** URI: ipp://localhost:8000/ipp/print/<printer_name> , where <printer_name> is the printer name chosen in printer application
|
||||
|
||||
. Remote print queues on a print server:
|
||||
* URI: ipp://<server_ip_or_server_hostname>:631/printers/<remote_print_queue> , where <server_ip_or_server_hostname> is server's IP address or hostname and <remote_print_queue> is a name of the print queue installed on the server
|
||||
* it depends on CUPS on the server whether a local printer which points to a printer on the server can be installed as IPP Everywhere model - usually CUPS 2.2.8 and newer support driverless and some distributions such as CentOS 8 backported the functionality as well
|
||||
* otherwise it depends on printer's driver on the old server - the key is to prevent applying the options multiple times (so one of the connections has to be raw and loses some of the functionality)
|
||||
|
||||
. Legacy or specialized printers
|
||||
* (deprecated, to be removed in CUPS 3.0) can be discovered by CUPS and installed with classic drivers
|
||||
* can be installed in printer application and then installed in CUPS as a permanent queue (see driverless printers - printers installed via printer application above)
|
||||
|
||||
==== Driverless options don't do the trick for me on my driverless printer, I want to use features from the driver
|
||||
|
||||
The current recommended action is to install the printer via xref:_how_to_install_a_printer_via_printer_application_in_snap_and_making_it_available_for_cups[printer application], which contains the classic driver, because installation the printer permanently in CUPS with classic driver is deprecated and it will be removed in CUPS 3.0. Then mDNS can be used to catch it by CUPS or the printer from printer application has to be installed permanently in CUPS as a IPP Everywhere printer.
|
||||
|
||||
In case of IPP-over-USB printers, a reject rule has to be added as described in xref:cups-known-issues.adoc#_usb_printerscanner_doesnt_work_due_a_conflict_on_usb_port[known issues].
|
||||
|
||||
==== I install the printer on a server, which will share the printer further
|
||||
|
||||
Printers on the server have to be installed xref:_how_to_install_a_permanent_print_queue[permanently] to be shared. IPP Everywhere model (directly to the printer or via printer application) is the ideal, but a classic driver with standardized PPD options on a server capable of using driverless is fine as well - clients can use IPP Everywhere model when pointing to the server and options are translated properly. Otherwise there is a possibility that some options aren't applied or applied twice. Don't forget about enabling IPP in firewall, setting ACLs to the server via [filename]`/etc/cups/cupsd.conf` and attaching the daemon to port 631 instead of localhost.
|
||||
|
||||
==== I'm in a company with old print server incapable of driverless, I want to print
|
||||
|
||||
The important thing is to prevent applying options multiple times in this scenario. There are several ways how to do it:
|
||||
|
||||
* ask your IT support for the driver (print queue on the server has to be raw)
|
||||
* use *ServerName* directive in [filename]`/etc/cups/client.conf` or *CUPS_SERVER* environment variable to connect to the server directly - you won't be able to do admin tasks, but capable of printing.
|
||||
|
||||
=== How to find out whether my printer is capable of driverless printing?
|
||||
|
||||
Network printers have the prerequisites - enablement of IPP port on the printer is the minimum, mDNS is required for automatic printer discovery by `libcups`.
|
||||
|
||||
* [command]`ipptool` command which sends IPP Get-Printer-Attributes request to the network printer passes:
|
||||
|
||||
----
|
||||
$ ipptool -tv ipp://printer.example.com:631/ipp/print get-printer-attributes.test
|
||||
"/usr/share/cups/ipptool/get-printer-attributes.test":
|
||||
Get-Printer-Attributes:
|
||||
attributes-charset (charset) = utf-8
|
||||
attributes-natural-language (naturalLanguage) = en
|
||||
printer-uri (uri) = ipp://printer.example.com:631/ipp/print
|
||||
requested-attributes (1setOf keyword) = all,media-col-database
|
||||
Get printer attributes using get-printer-attributes [PASS]
|
||||
...
|
||||
----
|
||||
|
||||
, where `printer.example.com` is the hostname or IP of your network printer,
|
||||
|
||||
* look for AirPrint among device specification,
|
||||
* https://www.pwg.org/printers/[Officially certified printers for IPP Everywhere],
|
||||
* check xref:_how_to_setup_cups_temporary_queues_with_network_printer[manual] for enabling CUPS temporary queues - if your printer is seen in the end in CUPS commands that way, your printer is capable of driverless printing,
|
||||
* [USB devices only] check for IPP over USB (xref:_how_to_find_out_if_my_usb_device_supports_ipp_over_usb[manual] here).
|
||||
|
||||
=== How to find out if my USB device supports IPP over USB
|
||||
|
||||
Check whether your USB device has a following text in [command]`lsusb -v` output:
|
||||
|
||||
----
|
||||
...
|
||||
bInterfaceClass 7 Printer
|
||||
bInterfaceSubClass 1 Printer
|
||||
bInterfaceProtocol 4
|
||||
iInterface 0
|
||||
...
|
||||
----
|
||||
|
||||
If the device has the _bInterfaceClass 7_, _bInterfaceSubClass 1_ and _bInterfaceProtocol 4_ in the sequence, it supports IPP over USB which is critical for USB device driverless printing and scanning.
|
||||
|
||||
=== How to setup CUPS temporary queues
|
||||
|
||||
To setup the temporary queues correctly, there are several prerequisities:
|
||||
|
||||
* printer/remote print queue has a driverless support and has it enabled,
|
||||
* your PC has avahi-daemon service or avahi-daemon socket running,
|
||||
* your PC has cups socket or service running,
|
||||
* mDNS hostnames are resolvable - test by pinging a .local hostname
|
||||
|
||||
==== How to setup CUPS temporary queues with network printer
|
||||
|
||||
* additional requirement:
|
||||
** enable MDNS in your firewall settings
|
||||
|
||||
After this the temporary queue will appear in the print dialog and you don't need to install a specific print queue unless you have a reason for it.
|
||||
|
||||
You can check if your printer is seen in mDNS messages by (*avahi-tools* must be installed):
|
||||
|
||||
----
|
||||
$ avahi-browse -avrt
|
||||
...
|
||||
= enp0s25 IPv4 HP LaserJet M1536dnf MFP (42307C) _ipp._tcp local
|
||||
hostname = [NPI42307C.local]
|
||||
address = [192.168.1.10]
|
||||
port = [631]
|
||||
txt = ["UUID=434e4239-4243-4a42-5859-3c4a9242307c" "Scan=T" "Duplex=T" "Color=F" "note=" "adminurl=http://NPI42307C.local." "priority=10" "product=(HP LaserJet M1536dnf MFP)" "ty=HP LaserJet M1536dnf MFP" "URF=CP99,W8,OB10,PQ3-4-5,DM1,IS1-4,MT1-2-3-5,MT1-2-3-5,RS600" "rp=ipp/printer" "pdl=application/postscript,application/vnd.hp-PCL,application/vnd.hp-PCLXL,application/pdf,image/urf" "qtotal=1" "txtvers=1"]
|
||||
...
|
||||
----
|
||||
|
||||
and if CUPS or its backends see the printer by commands:
|
||||
|
||||
(lists all existing print queues - permanent or temporary)
|
||||
|
||||
----
|
||||
$ lpstat -e
|
||||
HP_LaserJet_M1536dnf_MFP_42307C_
|
||||
----
|
||||
|
||||
or
|
||||
|
||||
(lists all devices, which CUPS sees in the local network or USB)
|
||||
|
||||
----
|
||||
$ lpinfo -l -v
|
||||
...
|
||||
Device: uri = ipp://HP%20LaserJet%20M1536dnf%20MFP%20(42307C)._ipp._tcp.local/
|
||||
class = network
|
||||
info = HP LaserJet M1536dnf MFP (driverless)
|
||||
make-and-model = HP LaserJet M1536dnf MFP
|
||||
device-id = MFG:HP;MDL:LaserJet M1536dnf MFP;CMD:PDF,PS,PCL,AppleRaster,URF;
|
||||
location =
|
||||
...
|
||||
----
|
||||
|
||||
==== How to setup CUPS temporary queues with USB printer
|
||||
|
||||
* additional requirements:
|
||||
** install *ipp-usb*, which will transform IPP over USB devices to network printer on localhost:
|
||||
|
||||
----
|
||||
$ sudo dnf -y install ipp-usb
|
||||
----
|
||||
|
||||
Then you can follow the steps in xref:_how_to_setup_cups_temporary_queues_with_network_printer[manual] for network printers.
|
||||
|
||||
=== How to install a permanent print queue
|
||||
|
||||
Prerequisties for permanent driverless printers: enable IPP in your firewall, enable IPP on your printer if possible.
|
||||
|
||||
==== Installation via CUPS web UI ====
|
||||
|
||||
* start cups.service
|
||||
|
||||
----
|
||||
$ sudo systemctl start cups
|
||||
----
|
||||
|
||||
* go to *http://localhost:631* in your browser
|
||||
* go to *Administration* tab
|
||||
* click on *Add printer*
|
||||
* enter your credentials
|
||||
* choose the found device or the connection you prefer - for driverless permanent queue choose *Internet Printing Protocol (ipp)*
|
||||
* in case you didn't choose a found device, enter the device uri at the next page - for driverless printers they usually are:
|
||||
|
||||
----
|
||||
Network printers:
|
||||
ipp://<printer_IP_or_printer_hostname>:631/ipp/print
|
||||
|
||||
USB printers via ipp-usb:
|
||||
ipp://localhost:60000/ipp/print
|
||||
|
||||
Non-driverless printers via printer application:
|
||||
ipp://localhost:8000/ipp/print/<printer_name>
|
||||
|
||||
Printers pointing to a remote CUPS server:
|
||||
ipp://<server_ip_or_server_hostname>:631/printers/<remote_print_queue>
|
||||
----
|
||||
|
||||
* choose device manufacturer and model (*IPP Everywhere* for driverless printers)
|
||||
* set a different default options if needed and finish
|
||||
|
||||
*Notes:*
|
||||
|
||||
Adding a permanent queue for driverless USB printers or non-driverless printers installed in a printer application is usually unnecessary, because they are shared by mDNS on localhost, so any application using CUPS 2.0+ API functions (cupsGetDests(), cupsGetNamedDest(), cupsCopyDestInfo()) should be able to pick them automatically (for network printer it depends whether the device is in the same subnet as your machine). Installling them permanently should be necessary only if an application doesn't use the recent API or to work around a bug which happens when using them as temporary queues.
|
||||
|
||||
If there are more devices via *ipp-usb* or printer applications, they listen on different ports - devices via ipp-usb start on port 60000, separate printer applications start on port 8000.
|
||||
|
||||
|
||||
==== Installation via CLI commands ====
|
||||
|
||||
* you will need a device uri - `<device_uri>`, which you can find by `lpinfo -v`:
|
||||
|
||||
----
|
||||
$ lpinfo -v
|
||||
direct usb://HP/Officejet%20Pro%208500%20A909a?serial=NNNNNNNNN&interface=1
|
||||
====================================================================
|
||||
network dnssd://Officejet%20Pro%208500%20A909a%20%5B43FD8E%5D._pdl-datastream._tcp.local/
|
||||
=================================================================================
|
||||
----
|
||||
|
||||
or construct it manually - f.e. for IPP printers:
|
||||
|
||||
----
|
||||
ipp://<IP/hostname>:631/ipp/print
|
||||
----
|
||||
|
||||
and a driver name - `<driver>`, f.e.:
|
||||
|
||||
----
|
||||
$ lpinfo -m
|
||||
....
|
||||
everywhere IPP Everywhere
|
||||
==========
|
||||
...
|
||||
----
|
||||
|
||||
----
|
||||
$ lpadmin -p <name> -v <device_uri> -m <driver> -E
|
||||
----
|
||||
|
||||
where `<device_uri>` and `<driver>` are underscored strings from previous commands and `<name>` is a print queue name, which is chosen by you.
|
||||
|
||||
== How to install a printer via printer application in SNAP and making it available for CUPS
|
||||
|
||||
Currently printer applications are available in SNAPs on Fedora. I'm planning to release them as RPMs, but the code base will be the same, so its testing can happen even with SNAPs.
|
||||
|
||||
* install snapd,
|
||||
|
||||
First we have to install snapd for testing purposes:
|
||||
|
||||
----
|
||||
$ sudo dnf -y install snapd
|
||||
$ sudo ln -s /var/lib/snapd/snap /snap
|
||||
$ snap version
|
||||
----
|
||||
|
||||
If the installation had been successful, the last command will show snapd's version.
|
||||
|
||||
* install and run printer application,
|
||||
|
||||
First the SNAP with printer application has to be installed and started by the commands below. All printer applications are available in SNAP Store under the same names as they are at https://github.com/orgs/OpenPrinting/repositories[OpenPrinting repositories]. We will use [filename]`ps-printer-app` printer application in the next steps.
|
||||
|
||||
----
|
||||
$ sudo snapd install --edge ps-printer-app
|
||||
$ sudo snapd run ps-printer-app
|
||||
----
|
||||
|
||||
* go to http://localhost:8000,
|
||||
|
||||
After starting the printer application its web interface becomes available at http://localhost:8000 - if user installs and runs another printer application, it will become available at localhost on the next port (8001). The printer application can contain several printers (as [filename]`cupsd` does).
|
||||
|
||||
* click on `Add Printer` on the main page,
|
||||
* choose the printer's name,
|
||||
* select the found device or choose `Network printer` from `Device` scroll menu and provide hostname or IP of the device,
|
||||
* choose to auto-detect driver or select the driver by yourself,
|
||||
* click on `Add Printer`,
|
||||
* now the printer should be available at least on localhost via mDNS (if [filename]`avahi-daemon` is running and `nss-mdns` is installed)- check it by [filename]`avahi-browse`(`avahi-tools` has to be installed):
|
||||
|
||||
----
|
||||
$ avahi-browse -avrt
|
||||
...
|
||||
= lo IPv4 HP Laserjet M1536 _ipp._tcp local
|
||||
hostname = [fedora-2.local]
|
||||
address = [127.0.0.1]
|
||||
port = [8000]
|
||||
txt = ["Scan=F" "PaperMax=legal-A4" "Fax=F" "product=(HP LaserJet M1536dnf MFP Postscript (recommended))" "mopria-certified=1.3" "priority=0" "qtotal=1" "txtvers=1" "Duplex=T" "Color=F" "TLS=1.2" "URF=V1.5,W8,PQ3-4-5,DM1,FN3,IS0-20,MT1-5-6-3,OB10,RS300-600" "UUID=24837a30-5f87-3ac9-6d85-086d486092dd" "pdl=image/pwg-raster,image/urf,application/vnd.printer-specific,application/pdf,application/postscript,image/jpeg,image/png" "note=" "adminurl=http://fedora-2.local:8000/HP_Laserjet_M1536/" "ty=HP LaserJet M1536dnf MFP Postscript (recommended)" "rp=ipp/print/HP_Laserjet_M1536"]
|
||||
...
|
||||
----
|
||||
|
||||
* and by `lpstat -e`:
|
||||
|
||||
----
|
||||
$ lpstat -e
|
||||
...
|
||||
HP_Laserjet_M1536
|
||||
...
|
||||
----
|
||||
|
||||
The available printing options for the printer installed via printer application can be checked with [filename]`lpoptions` command:
|
||||
|
||||
----
|
||||
$ lpoptions -p HP_Laserjet_M1536 -l
|
||||
PageSize/Media Size: 184.15x260mm 195.09x269.88mm A4 A5 B5 DoublePostcardRotated Env10 EnvC5 EnvDL EnvMonarch Executive FanFoldGermanLegal ISOB5 Legal *Letter Postcard roc16k Custom.WIDTHxHEIGHT
|
||||
InputSlot/Media Source: *Auto Tray1 Auto
|
||||
MediaType/Media Type: *Unspecified Stationery Light6074 MidWeight96110 Heavy111130 ExtraHeavy131175 MonochromeLaserTransparency Labels StationeryLetterhead Envelope StationeryPreprinted Prepunched Colored Bond StationeryRecycled Rough Vellum
|
||||
cupsPrintQuality/cupsPrintQuality: Draft *Normal High
|
||||
ColorModel/Output Mode: *Gray
|
||||
Duplex/Duplex: *None DuplexNoTumble DuplexTumble
|
||||
OutputBin/OutputBin: *FaceDown
|
||||
----
|
||||
|
||||
== How to install a scanner
|
||||
|
||||
Scanners in Linux don't have to be installed the same way as printers are if they are in the same network or connected via USB - you just need *sane-backends* to be installed and any scanning application will communicate with scanner/multifunction device via the backend which supports the scanner.
|
||||
|
||||
However, the older HP scanners and multifunction devices require an additional package - *hplip* - and its binary plugins downloaded via [command]`hp-plugin -i` if they aren't supported by sane-backends already.
|
||||
|
||||
=== How to find out my multifunction device or standalone scanner is capable of driverless scanning?
|
||||
|
||||
* check the device specification and look for eSCL/AirScan/WSD - if any of these are mentioned, the device is capable of driverless scanning
|
||||
* most devices which advertise they can do AirPrint are capable of AirScan too
|
||||
* [USB devices only] check for IPP over USB (xref:_how_to_find_out_if_my_usb_device_supports_ipp_over_usb[manual] here).
|
||||
|
||||
=== How to make driverless scanning work
|
||||
|
||||
For LAN located and USB devices:
|
||||
|
||||
* have *avahi-daemon* enabled and running
|
||||
|
||||
----
|
||||
$ sudo systemctl enable avahi-daemon
|
||||
$ sudo systemctl start avahi-daemon
|
||||
----
|
||||
|
||||
* enable MDNS in firewall
|
||||
* [USB devices only] install *ipp-usb*
|
||||
|
||||
For network scanners in a different network:
|
||||
|
||||
* set the scanner device uri in [filename]`/etc/sane.d/airscan.conf` - see:
|
||||
|
||||
----
|
||||
man sane-airscan
|
||||
----
|
||||
|
||||
== How to setup mDNS with systemd-resolved
|
||||
|
||||
systemd-resolved is enabled and running by default since F33 and can be setup to work with Avahi on mDNS support which CUPS needs - Avahi does the advertising, registering and sharing devices, and resolved will handle '.local' address resolution. It will work with following steps:
|
||||
|
||||
* put [option]`MulticastDNS=resolve` into [filename]`/etc/systemd/resolved.conf`
|
||||
|
||||
----
|
||||
$ sudo systemctl restart systemd-resolved
|
||||
$ sudo nmcli connection modify <connection_name> connection.mdns yes connection.llmnr yes
|
||||
$ sudo systemctl restart NetworkManager
|
||||
----
|
||||
|
||||
== How to compress files
|
||||
|
||||
Example:
|
||||
|
||||
----
|
||||
$ tar -czvf cups-information.tar.gz /etc/cups cups.logs troubleshoot.txt lpinfo.log
|
||||
----
|
||||
|
||||
== Restarting cups service
|
||||
|
||||
You restart cups service with:
|
||||
|
||||
----
|
||||
su -c 'systemctl restart cups.service'
|
||||
----
|
||||
|
||||
|
|
|
|||
|
|
@ -1,4 +1,10 @@
|
|||
= How to debug Wayland problems
|
||||
N.N.
|
||||
:revnumber: unspecified
|
||||
:revdate: 2020
|
||||
:category: Troubleshooting
|
||||
:tags: How-to, Workstation, Wayland
|
||||
//:imagesdir: ./images
|
||||
|
||||
//FIXME * xref:debug-wayland-problems.adoc[How to debug Wayland problems] - note: maintained on wiki, does not fit quick-docs IMHO
|
||||
|
||||
|
|
|
|||
|
|
@ -1,8 +1,31 @@
|
|||
ifdef::context[:parent-context: {context}]
|
||||
:context: disabling-automatic-screenlock
|
||||
|
||||
= Disabling the GNOME automatic screen locking
|
||||
Oğuz Ersen
|
||||
:revnumber: F31,F32
|
||||
:revdate: 2020-04-09
|
||||
:category: Administration
|
||||
:tags: How-to, Customization, Workstation, Gnome
|
||||
|
||||
include::{partialsdir}/proc_disabling-gnome-screenlock.adoc[leveloffset=+1]
|
||||
ifdef::parent-context[:context: {parent-context}]
|
||||
ifndef::parent-context[:!context:]
|
||||
|
||||
|
||||
In the interest of safety and privacy, the GNOME automatic screen lock is enabled by default.
|
||||
|
||||
When the screen locks after a period of inactivity, you must enter your password to unlock the screen.
|
||||
|
||||
You can disable this feature at any time.
|
||||
|
||||
To disable the GNOME automatic screen lock, complete the following steps.
|
||||
|
||||
For Fedora 31 (GNOME 3.34):
|
||||
|
||||
. On the desktop, navigate to the upper-right corner of the screen, click the arrow icon to expand the desktop options and then click the *Settings* icon.
|
||||
. From the the *Settings* menu, select *Privacy*.
|
||||
. On the *Privacy* page, select *Screen Lock*, and toggle the *Automatic Screen Lock* switch from *On* to *Off*.
|
||||
. Close the window and verify that in the *Privacy* page, the *Screen Lock* is *Off*.
|
||||
|
||||
For Fedora 32 (GNOME 3.36):
|
||||
|
||||
. On the desktop, navigate to the upper-right corner of the screen, click the arrow icon to expand the desktop options and then click *Settings*.
|
||||
. From the *Settings* menu, select *Privacy*, and then select *Screen Lock*.
|
||||
. On the *Screen Lock* page, toggle the *Automatic Screen Lock* switch from *On* to *Off*
|
||||
|
||||
To enable the automatic screen lock, repeat this process and toggle the switch from *Off* to *On*.
|
||||
Loading…
Add table
Add a link
Reference in a new issue